Counterbalancing device



March 27, 1934 R. R. BLOSS El AL 50 I COUNTERBALANCING DEVICE Original Filed Oct. 26, 1927 s Sheets-Sheet 1 IN EN TORS P/cfiar R 5/055. Pay C Pba/ March 27, 1934.

R. R. BLOSS ET AL- COUNTERBALANCING DEVICE Original Filed Oct, 26, 1927 3 Sheets-Sheet 2 V EN TORS IN ara ATTORNE$\ March 1934- R. R. BLoss ET AL COUNTERBALANCING DEVICE 3 Sheets-Sheet 3 Original Filed Oct. 26, 1927 -lNVENTORS P/c araEB/pss.

/Po 6? P/7@// 6 A TTORNEY Patented Mar. 27, 1934 PATENT OFFICE COUNTERBALANCING DEVICE Richard R. Bloss and Roy 0. Pfeil, Columbus, Ohio, assignors to The International Derrick & Equipment Company, Columbus, Ohio, a corporation of Ohio Original application October 26, 1927, Serial No.

Divided and this application April 6, 1928, Serial No. 268,027

5 Claims.

Our invention relates to a counterbalancing device and, more particularly, to a counterbalancing device that is attached to and operates in conjunction with the crank of an oil well drilling and 5 pumping mechanism.

This is a division of our application, Serial Number 228,963, filed October 26, 1927.

Certain features of adjustability have been provided in order to meet the normal variations in the weight of the suspended pumping or drilling mechanism and the oil or other fluid above the plunger. Also, features of adjustability have been provided whereby the counterbalance effect may be synchronized with the reactions in the pitman that result from the sucker rod pull. These features of adjustability are calculated to make it possible to eliminate the jerky movements of the various parts of the drilling and pumping mechanism and thereby provide a smooth and uniform operation throughout all cycles of such pumping or drilling.

The fact that our counterbalance is so designed as to be attached to and operate with the crank has decided advantages over a band wheel or walking beam counterbalance. Some of these advantages reside in the fact that the wear and tear on the band wheel and walking beam and the torsional stress on the crank shaft, as produced by ordinary types of the band wheel or walking beam counterbalance, are eliminated.

- With our design and construction, we avoid unusual stress on any part of the drilling and pumping mechanism with the exception of the crank arm itself.

Other advantages of our device reside in the fact that our counterbalance, being so designed as to be attached to and operate with the crank, is located outside of the rig house whereby it may be readily adjusted and operated. It is so constructed that it may be quickly and easily'shifted in an arcuate path with relation to the crank arm to synchronize the counterbalance effect with the load.

In our invention, we have provided a plurality 5 of weight members that may be attached to or detached from the counterbalance. Such weights are provided so as to obtain a greater or lesser counterbalancing effect since, by varying the number of weight members and thereby varying the mass of weight of the counterbalance, any desired counterbalancing effect may be obtained.

Also, we have provided a counterbalancing device of such construction that the counterbalance unit may be attached to or detached from the crank arm and have provided means for positively maintaining the counterbalance unit in an inoperative and non-interfering position with respect to such arm.

Various other advantageous features will appear from the following detailed description and the preferred embodiment of our invention may be seen in the accompanying drawings wherein similar characters of reference designate corresponding parts and wherein:

Figure 1 is a side view showing the application of our invention to an ordinary drilling and pumping rig structure.

Figure 2 is a perspective view of the preferred embodiment of our invention.

Figure 3 is a perspective view of the latch which we employ to positively maintain the counterbalancing unit in inoperative and non-interfering position with respect to the crank arm.

Figure 4 is a side view, partly in section, showing the counterbalancing unit in cooperative relation with the crank arm of an oil well drilling or pumping mechanism.

Figure 5 is a view similar to Figure 3 but showing the counterbalancing unit in a position of inoperative relation with the crank arm of an oil well drilling or pumping mechanism and showing the latch in a position to prevent the counterbalancing unit from entering into cooperative re lation with the crank arm or from interfering therewith.

Figure 6 is a front elevation of the counterbalancing unit.

Figure '7 is an end elevation of a part of an oil well drilling and pumping mechanism with our counterbalancing device attached thereto.

Referring to the drawings, particularly to Figure 1, we have shown the usual drilling rig structure comprising the engine house 1, belt house 2, band wheel house 3 and derrick structure 4. In this figure and in Figure 7, we have shown a novel counterbalancing unit 5 as being disposed on the outside of the house 3 which encloses the band wheel 6'. A sand reel 7 is also disposed. on the outside of the house 3. I

As best shown in Figure 2,. a crank arm 8 is mounted upon and keyed to a crank shaft 9 which, in turn, operates in a bearing 10 that may be supported in a jack-post or similar structure 11.

The counterbalance unit 5 is shown as being mounted on the hub of the crank arm 8 in a position between the main body portion of the crank arm 8 and the jack-post or similar supporting structure 11 by means of the split bearing 12. However, it will be understood that the counterbalance unit 5 may be mounted directly on the crank shaft 9 if desired. Such counterbalance unit is provided with a plurality of tapered sockets 13 which cooperate with a tapered boss Men the crank arm 8 and provide a means for adjusting the weight center of the counterbalance unit to a multiplicity of positions with respect to the crank arm.

In the lower part of the counterbalance unit, a plurality of holes 15 are provided as a means whereby supplemental weight elements 16 may be attached to or detached from the counterbalance unit as desired. These supplemental weight elements 16 may be attached to the counterbalance unit in any desired number by means of bolts 17. A pitman 18 that may be of any preferred form but is preferably of the form shown in Figures 1 and 2 is shown as being attached to the crank arm 8 by means of a wrist pin 19. A plurality of holes 20 are provided to permit adjustment of the wrist pin to different positions along the crank arm.

Referring to Figures 4 and 5 of the drawings, we have shown the counterbalance unit 5 in both operative and inoperative relation to the crank arm 8. As shown in Figure 4, the tapered boss 14 is fitted in one of the tapered sockets 13 and a bolt 21 passes through the counterbalance .unit and the crank to hold the tapered boss within the tapered socket in which it is disposed. A latch 22 that is hinged to the upper part of the slit bearing 12 is shown in raised or inoperative position.

Referring to Figure 5, the counterbalance unit 5 is shown in inoperative position with relation to the crank arm 8. This is accomplished by removing the bolt 21 and moving the counterbalance unit along the shaft 9 away from the crank arm 8 enough so that the tapered boss 14 will be disengaged from the tapered socket 13. At this time, the latch 22 is manually moved to such a position that it will be between the shoulder 23 of the crank and the shoulder 24 of the counterbalance unit bearing to prevent return movement of the counterbalance unit. The crank may then be rotated independently of the counterbalance unit. In order that the counterbalance unit may be moved away from the crank more easily, the portion' of the hub of the crank on which the counterbalance unit is suspended may be machined so as to taper slightly in a direction away from the crank.

By referring to the preceding description and the drawings attached hereto, it will be clearly understood that we have provided a counter balance unit that will permit dilferent counterbalancing effects to be obtained. The desired counterbalancing effect may be obtained by several adjustments, the most simple of which would be by swinging the counterbalance unit and the crank with relation to each other until the tapered boss 14 on the crank arm 8 is in cooperative relation to the desired tapered socket 13 in the counterbalance unit. Another means of obtaining the desired counterbalancing eiiect is to vary the number of the supplemental weight elements on the counterbalance unit 5. Still another means of obtaining the desired counterbalancing effect is by adjusting the wrist pin of the pitman 18 to various positions along the crank arm 8.

Also, by referring to 'Figure 1 of the drawings, it will be apparent that our counterbalance unit, when assembled, is located outside of the band wheel house 3 whereby it may be readily adjusted and operated, and not inside where the space is "cramped'and the counterbalance device would be more or less inaccessible. The siding of the band wheel house 3 is preferably between the sprocket wheel 25 which provides a means for driving the sand reel '7 and the jack-post or similar supporting structure, as shown best in Figure 7. Furthermore, our device is so constructed that the counterbalance unit may be quickly and easilyshifted in an arcuate path, with relation to the crank arm, to synchronize the counterbalance effect with the load.

To those familiar with the art, it will be clearly understood that we have provided a counterbalancing device whereby any desired counterbalancing effect may be obtained and have provided a means whereby this counterbalancing device may be moved and positively maintained out of operative and interfering relation with the other mechanical parts of the drilling or pumping structure. It will also be clear that, by providing means for altering the position of the counterbalance unit with respect to the crank, We have provided a counterbalance that makes it possible to synchronize the counterbalance effect with the reactions in the pitman that result from the sucker rod pull.

It will be seen that we have provided a counterbalance element which may be drawn into rigid relation to the crank by means of a tapered boss designed to fit in any of the complementally tapered sockets. The boss is large and, therefore, has a large shearing area. It permits the use of bolts for securing the crank and counterbalance together and, at the same time, the tapered boss and sockets ensure a very tight fit which cannot be economically obtained by the use of bolts alone.

It will also be apparent that our counterbalance is so designed as to be attached to and operate with the crank of an oil Well drilling and pumping mechanism and that this has decided advantages over a band wheel or walking beam counterbalance. One of these advantages resides in the fact that the crank may be assembled with the crank shaft in the factory. By assembling the crank and crank shaft in the factory, it is possible to do so either hydraulically or by attaching the crank to the crank shaft by a shrink fit, both of which operations are impractical when the crank and crank shaft are assembled in the field. A much more rigid assemblage is thereby obtained.

Another advantage resides inthe fact that the wear and tear on the band wheel and the torsional stress upon the crank shaft, such as produced by ordinary types of band wheel or walking beam counterbalances, are eliminated. To visualize the strain to which the various parts of the apparatus are put, it is well to appreciate that in order to have the proper counterbalancing effect in oil well drilling and pumping mechanism, it is usually necessary to provide a Weight of approximately four tons, the center of gravity of which is usually 5 feet from the center of the shaft. weight directly to the crank, which eliminates practically all of those stresses on the band wheel, keys, crank shaft and associated parts due to the presence of a counterbalance weight attached to the band wheel.

Still another advantage of our invention resides in the fact that only a relatively short time is required to attach and detach our counterweight to or from. the crank and, consequently, to or from a position of effectiveness. This is very important because it is well known that,

when a pump is not operated in. a well, water has a tendency to encroach on. the well and adjacent wells act to pull the oil away from the well which is not being pumped. Therefore, to cease pumping a well results in the necessity for a considerable amount of pumping before the well will be in the condition it was in prior to the time that the pumping ceased.

A further advantage resides in the fact that our design and construction is such that the counterbalance weight is placed at a maximum distance from the center of the crank shaft. Obviously, the further the counterbalance weight is removed from the center of the crank shaft the less weight is required. Therefore, our device will permit a relatively small counterbalance weight to be used to obtain a relatively large counterbaiancing effect.

Having thus described our invention, what we claim is:

1. In combination, a crank shaft for a pumping mechanism, a crank arm on said crank shaft, a weight structure suspended from said crank shaft adjacent said crank arm, means for directly connecting said crank arm' to said weight structure to prevent relative movement thereof, said weight structure being adjustable axially of said crank shaft to a position of spaced inoperative relation to said crank arm, and means for maintaining said weight structure in such spaced inoperative relation.

2. In combination, a crank shaft of a pumping mechanism, a crank arm on said crank shaft, a support for said crank shaft, a counterbalance weight supported by said crank shaft in between said support and said crank arm, said counterbalance weight structure being adjustable axially along the crank shaft either to a position for directly connecting it to said crank arm so that it may rotate therewith or to a position of spaced inoperative relation to said crank arm, and means for positively maintaining said weight structure out of cooperative or interfering relation with said crank arm.

3. In combination, a crank shaft of a pumping mechanism, a crank arm on said crank shaft, a support for said crank shaft, a counterbalance weight structure supported by said crank shaft in between said support and said crank arm, said counterbalance weight structure being adjustable either to a position for directly connecting it to said crank arm so that it may rotate therewith or to a position of spaced inoperative relation'to said crank arm, and a locking hook mounted on said counterbalance weight structure and movable into a position to maintain said counterbalance weight structure away from operative or interfering relation with said crank arm.

4. In combination, a crank shaft of a pumping mechanism, a crank arm on said crank shaft, a housing through the wall of which said crank shaft projects with the crank arm on the outside thereof and spaced therefrom, a support for said crank shaft, and a counter weight structure disposed between said crank arm and the wall of such housing and being normally supported by said crank shaft in such a position that it can be attached to said crank arm, and means for attaching said counter weight structure to said crank arm, said weight structure being adjustable axially of the crank shaft to a position of spaced inoperative relation to said crank arm, and means for maintaining said weight structure in spaced inoperative relation to said crank arm.

5. In combination, a crank shaft for a pumping mechanism, a crank arm on said crank shaft, a pitman connected to said crank arm, a support for said crank shaft, and a counterbalance weight suspended from said crank shaft in between said crank arm and said crank shaft support, and

means for connecting said weight to said crank arm, said weight being adjustable axially of said shaft away from said crank arm and means for maintaining said weight away from said crank arm.

RICHARD R. BLOSS. ROY C. PFEIL. 

